.\" $OpenBSD: RSA_meth_new.3,v 1.3 2018/09/12 15:09:22 jmc Exp $
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.Dd $Mdocdate: September 12 2018 $
.Dt RSA_METH_NEW 3
.Os
.Sh NAME
.Nm RSA_meth_new ,
.Nm RSA_meth_dup ,
.Nm RSA_meth_free ,
.Nm RSA_meth_get_finish ,
.Nm RSA_meth_set1_name ,
.Nm RSA_meth_set_finish ,
.Nm RSA_meth_set_priv_enc ,
.Nm RSA_meth_set_priv_dec
.Nd build up RSA methods
.Sh SYNOPSIS
.In openssl/rsa.h
.Ft RSA_METHOD *
.Fo RSA_meth_new
.Fa "const char *name"
.Fa "int flags"
.Fc
.Ft RSA_METHOD *
.Fo RSA_meth_dup
.Fa "const RSA_METHOD *meth"
.Fc
.Ft void
.Fo RSA_meth_free
.Fa "RSA_METHOD *meth"
.Fc
.Ft int
.Fo RSA_meth_set1_name
.Fa "RSA_METHOD *meth"
.Fa "const char *name"
.Fc
.Ft int
.Fn "(*RSA_meth_get_finish(const RSA_METHOD *meth))" "RSA *rsa"
.Ft int
.Fo RSA_meth_set_finish
.Fa "RSA_METHOD *meth"
.Fa "int (*finish)(RSA *rsa)"
.Fc
.Ft int
.Fo RSA_meth_set_priv_enc
.Fa "RSA_METHOD *meth"
.Fa "int (*priv_enc)(int flen, const unsigned char *from,\
 unsigned char *to, RSA *rsa, int padding)"
.Fc
.Ft int
.Fo RSA_meth_set_priv_dec
.Fa "RSA_METHOD *meth"
.Fa "int (*priv_dec)(int flen, const unsigned char *from,\
 unsigned char *to, RSA *rsa, int padding)"
.Fc
.Sh DESCRIPTION
The
.Vt RSA_METHOD
structure holds function pointers for custom RSA implementations.
.Pp
.Fn RSA_meth_new
creates a new
.Vt RSA_METHOD
structure.
A copy of the NUL-terminated
.Fa name
is stored in the new
.Vt RSA_METHOD
object.
Any new
.Vt RSA
object constructed from this
.Vt RSA_METHOD
will have the given
.Fa flags
set by default.
.Pp
.Fn RSA_meth_dup
creates a deep copy of
.Fa meth .
This might be useful for creating a new
.Vt RSA_METHOD
based on an existing one, but with some differences.
.Pp
.Fn RSA_meth_free
destroys
.Fa meth
and frees any memory associated with it.
.Pp
.Fn RSA_meth_set1_name
Stores a copy of the NUL-terminated
.Fa name
in the
.Vt RSA_METHOD
object after freeing the previously stored
.Fa name .
.Pp
.Fn RSA_meth_get_finish
and
.Fn RSA_meth_set_finish
get and set an optional function for destroying an
.Vt RSA
object.
Unless
.Fa finish
is
.Dv NULL ,
it will be called from
.Xr RSA_free 3 .
It takes the same argument
and is intended to do RSA implementation specific cleanup.
The memory used by the
.Vt RSA
object itself should not be freed by the
.Fa finish
function.
.Pp
.Fn RSA_meth_set_priv_enc
and
.Fn RSA_meth_set_priv_dec
set the functions used for private key encryption and decryption.
These functions will be called from
.Xr RSA_private_decrypt 3
and
.Xr RSA_private_encrypt 3
and take the same parameters as those.
.Sh RETURN VALUES
.Fn RSA_meth_new
and
.Fn RSA_meth_dup
return the newly allocated
.Vt RSA_METHOD
object or
.Dv NULL
on failure.
.Pp
All
.Fn RSA_meth_set*
functions return 1 on success or 0 on failure.
.Sh SEE ALSO
.Xr RSA_new 3 ,
.Xr RSA_private_decrypt 3 ,
.Xr RSA_private_encrypt 3 ,
.Xr RSA_set_method 3
.Sh HISTORY
These functions first appeared in OpenSSL 1.1.0.
.Fn RSA_meth_get_finish
and
.Fn RSA_meth_set1_name
have been available since
.Ox 6.4 ,
all the other functions since
.Ox 6.3 .
